Cold treatment apparatus and method



May 8, 1951 R. E. BLUDEAU 001.1) TREATMENT APPARATUS AND METHOD 5Sheets-Sheet 1 Filed July 26, 1946 lNVENTOR ROBERT E. BLUDEAU ATTORNEYR. E. BLUDEAU COLD TREATMENT APPARATUS AND METHOD May 8, 1951 Filed July26, 1946 3 Sheets-Sheet 2 INVENTOR ROBERT E.BLUDEAU ATTORNEY May 8, 1951R. E. BLUDEAU COLD TREATMENT APPARATUS AND METHOD 3 Sheets-Sheet 15Filed July 26, 1946 INVENTOR ROBERT E. BLUDEAU BY i ATTORNEY PatentedMay 8, 1951 co o TREATMENT APPARATUS AND METHOD E e E i ee East a e N-J-, a s w, by mesne assignments, to Union Carbide and CarbonCorporation, a corporation of New York Application July 26, 1946, SerialNo. 686,378

14 Claims.

This invention relates to an improved cold treatment apparatusandrnethod, and has for an object to increase the utility of suchapparatus adapting it for a wide variety of sizes and shapes of articlesto be cooled. Another object is to increase the degree of cooling towhich various sizes and shapes of articles may be subjected. =et anotherobject is to provide a simple, efficient and inexpensive apparatus foraccomplishi the previously mentioned purpose. A further object is toincrease the facility with which apparatus of this character may beoperated.

The e rabili f shi n art e to a v low temperature has beeome recognizedin shrink fi ting and fo the u p se i u a oxyn, oge or th r a e a e e nu e ed as the refrigerant for cooling the article by direct immersion.Likewise precooling of an article by flowing vaporized refrigerant overit prior to this immersion has been suggested. However, such priorsuggestions have not had the preliminary cooling chamber so independentof the immersion tank of liquid refrigerant that either may be usedalone or both used together efiiciently and for different sizes andshapes of articles without undue moisture deposition on them. It hasbeen discovered that most efiicient operation is possible when losses intemperature on transferring of an article from the precooling chamber tothe liquid refrigerant tank are a minimum and each is exposed to theatmosphere for a minimum time. To this end the chamber and tank arelocated close together and the closures to each open in oppositedirections so that not only may such transfer occur quickly but the lossof vaporized refrigerant through diffusion of the cold gas with warm airat room temperature be lessened by keeping the closures of the chamberand tank in closed position except during actual transfer. With smallarticles and holders these closures need not be open all the way to getthe article holders in and out of the tank and chamber. 4

Referring to the drawing:

Fig. l is a sectional elevation of one embodiment of this inventiontaken on the line I -I of Fig.2;

Fig. 2 is a top plan view of the device of Fig. l with parts brokenaway;

Fig. 3 is a right end view of the device of Fig. 2 with part of thehousing broken away;

Fig. l is a section on the line l-,4 of Fig 2.

A tank I l! for vaporized liquid refrigerant such as nitrogen, liquidair, or the like is located adjac nt the re liils ch mber 1. b9 2 1 bein10- 2 sa ed it n the a in r si n h rma insnlating material I3 is placedbetween thetank and chamber and between each and the casing. The tankIll preferably is provided with two closures l4 and I5 while the coolingchamber ll preferably has one closure l6. Surrounding the r pperopenings of the tank and chamber are packing strips l1 cooperating withthe closures in providing a fairly tight fit .to guard against undueleakage of vaporized refrigerant around the edges of the closures.

A filling connection 18 is located on the outside of the housing asshown in Figs. 1 and 2, the filling pipe l9 leading from this connection18 into the bottom portion of the tank Ill. As shown in Fig. 2 thisfilling pipe l9 has a bend in it to decrease expansion and contractionbe-, tween occasions when the tank is empty and free of refrigerant andtimes when it is filled.

Adjacent the bottom of the tank It is located an inwardly projectingflange 2D for supporting an object or article holder 21. The type ofarticle holder and the number of shelves it may carry depends on thesize and shape of the articles to be .cooled. vaporized refrigerantcoming from the liquid refrigerant in the tank Ill passes as indicatedby arrows through two gas passages 2. :doWn a passageway 23 formed in aside wall of the precooling chamber 1 to the lower portion of thelatter, thence .upward through the chamber H in contact with any objectstherein, and out a vent passage 24 to the atmosphere. l'he entrance ofthe vent passage 24 is near the ripper end of the chamber II butbelowthe closiire 16. The chamber .l 1, adjacent its bottom and abovethe outlet of passage 23, has an inwardly projecting flange 25 forsupporting the work holder 26 Ordinarily two work holders are adapted tosupport articles to be cooled in the precooling chamber. When filled tothe desired de ree @Pd $3995. 9 as a P ascribed sr qd he -hglq ma b mo mh precooling chamber and placed in the liquid refrigerant tank. Forchilling small articles four or more work holders will ordinarily beneeded. as one is removed from the immersion tank it is nnloaded andthen reloaded with articles to be cooled. Before the newly loaded holderis placed in the chamber I l a holder which has been in the coolingchamber a longer time is placed in the immersion tank to make room forthe newly q d da icl ol e The liquid tank l0 contains a partition 21,shown in Figs. ;2 and 4, extending from the clo- Mand 15 in conta t withopposit sides of the tank and downwardly to well below the normal liquidlevel and adjacent the bottom of the tank or to the top of thesupporting flange 20. Such a construction enables the liquid level oneach side of the partition to be equalized by static pressuretransmitted below the partition 21. An

1 advantage however for the partition is that it tends to localize thevapors of refrigerant where relatively warm objects are being immersedin only one side of the tank. As shown in Fig. 4 the upper edge of thepartition 21 is welded or otherwise secured to a channel member 28containing a block and the packing strips I! for cooperation with eachclosure !4 and i5.

The closures l4 and I are provided with hinges 29 adjacent one end ofthe housing l2 while the closure [6 for the precooling chamber hashinges 30 adjacent the opposite end of the housing. These closures areso hinged that they will swing open in opposite directions making itpossible for the operator to transfer an article holder from the chamberH to the tank In without having to lift the holder over either closurewhen open. As shown in Fig. 1 each closure is provided with a stop 3! tolimit the degree of opening and to assure each closure opening less than90, or in other words to insure that each closure automatically falls toits closed position when no longer held open.

Among the advantages of this invention may be mentioned the fact thatthe cooling chamber and immersion tank are functionally and structurallymore nearly independent of one another than has heretofore been thecustom, wherefore each is capable of separate use or both may be usedtogether, or one half of the tank It] may be used with the chamber H.Having the covers open oppositely facilitates the transfer of thearticle holders from the chamber l i into the tank In without having tolift them higher than enough to clear the top of the housing. Thepartition 21 makes the two parts of the tank more nearly separatefunctionally as to vapors. The apparatus illustrated is intended to useliquid nitrogen as the refrigerant, the spent gas for passing throughthe precooling chamber II is discharged to the atmosphere through thevent 24. Such a practice makes unnecessary the provision of any heatingor diluting apparatus such as has been proposed where liquid oxygen isused as the liquid refrigerant. The work holders are of course of a sizeadapted to fit within the openings in the top of the chamber II and thetank It] when the covers are raised. As illustrated this means thatthere may be some space in the precooling chamber l I between and notoccupied by the work holders. When this is so this space may be filledwith a stationary shelf 34 or removable shelves for supporting objectsindependently of the work holders. One purpose for such shelving is toretain special work which may be metallurgically changed with the use ofthe low temperature encountered. Having the covers in unstableequilibrium when not held open insures their being closed againstineflicient loss of vaporized refrigerant. The housing contains woodenbeams 32 on which the tank In and chamber H are mounted, the entirecabinet preferably being supported off the floor by legs 33.

While the principles and apparatus of this invention may be utilized invarious ways for cold treating metal and other articles, the particularapparatus disclosed herein has special advantages when the cold treatingoperation is performed in the following manner. At the start of anoperating period, two workpiece holders, containing one or moreworkpieces, are placed in the precooling chamber H. After the elapse ofa sufficient time for the workpieces to precool, these carriers aretransferred to the tank Ill and are severally immersed in the liquidrefrigerant below the two gas spaces separated by the partition 2", andtwo fresh workpiece holders are then placed in the precooling chamber Hto replace those transferred to the tank l0. After a sufficient coolingperiod has elapsed, one of the holders in the liquid is removed toutilize the cold workpieces in such holder, and this holder is replacedby a workpiece holder transferred from the precoolin chamber H. Then theother of the first holders in the liquid is removed therefrom to utilizethe cold workpieces in such holder, and this holder is replaced by theworkpiece holder that has been in the precooling chamber the longertime. Meanwhile fresh workpiece holders are successively placed in theprecooling chamber to replace those successively transferred to thetank. Thus, during normal operation, both sections of the liquid tankand the precooling chamber are loaded with workpiece holders (fouraltogether in this arrangement), and the holders are transferred andwithdrawn in the order of their coldness or the length of their coolingperiods, and they are replaced in similar sequence in the precoolingchamber, so that the operating cycle, once it has been initiated, willbe continuous.

This invention is better adapted for cooling larger objects than is theapparatus disclosed in the application of Bludeau and Buckman, SerialNo. 661,029, filed April 10, 1946, for Cold Treating Machine.

' I claim:

l. A cold treatment apparatus comprising, in combination, a tank for avaporizable liquid refrigerant, a cooling chamber outside of andlaterally displaced from said tank, said tank and chamber each having anopening through which an article may be inserted and withdrawn, amovable closure for each opening, a passage for vaporized refrigerantleading from an upper portion of said tank above a normal liquidleveltherein into an end portion of said chamber, and a vent for an endportion of said chamber remote from that into which said passage leadswhereby vaporized refrigerant under slight pressure in said tank maypass through said chamber in contact with an article therein and outsaid vent into the atmosphere.

2. A cold treatment apparatus comprising, in combination, a tank for avaporizable liquid refrigerant, a cooling chamber beside said tank, ahousing enclosing both the tank and chamber, thermal insulation betweenthe housing and tank and between the housing and chamber, a closure forsaid tank and a closure for said chamber to allow insertion andwithdrawal of work into and from the chamber and the tank, a passage forvaporized refrigerant leading from an upper portion of said tank above anormal liquid level therein and through such thermal insulation into alower portion of said chamber below any work therein being cooled, and avent in the upper portion of said chamber below the closure therefor forventing spent vaporized refrigerant into the atmosphere.

3. Apparatus according to claim 2 in which each closure moves away fromthe other in opening.

4. Apparatus according to claim 2 in which a bent filling pipe extendsfrom said tank through said insulation to the outside of said housingwhereby the bent portion of said pipe is adapted I to flex to compensatefor differences in length of. the pipe between periods of its use and.non-use.

5. Apparatus according to claim 2 in which said insulation is on atleast the sides and bot tom of said tank and chamber.

6. A cold treatment apparatus according to claim 2 in which a portion ofsaid passage is substantially parallel to and within an upstanding wallof said chamber and constituted in part by such wall.

7. Apparatus according to claim 2 in which said tank is provided withtwo spaced and independently operable closures and said chamber withonly one closure.

8. A cold treating apparatus, comprising a tank for liquid refrigerantin which an article to be cooled may be immersed in the liquid, saidtank having an opening above the liquid level through which said articlemay enter the liquid refrigerant, a removable cover for said opening, acooling chamber outside said tank having an opening through which anarticle be inserted for cooling, a removable cover for the chamberopening, a passage for vaporized refrigerant leading from said tankabove the liquid level to a lower end portion of the chamber and anotherpassage for vaporized refigerant leading from the opposite end portionof said chamber to that into which the vaporized refrigerant enters,whereby a slight pressure in said tank may sufiice to circulate cold gasthrough and out of the chamber.

9. A cold treating apparatus, comprising a tank for liquid refrigerantin which an article to be cooled may be immersed in the liquid, saidtank having an opening above the liquid level through which said articlemay enter the liquid refrigerant, a removable cover for said opening, acooling chamber outside said tank having an opening through which anarticle may be inserted for cooling, a removable cover for the chamberopening, a, passage for vaporized refrigerant leading from said tankabove the liquid level to an end portion of the chamber and anotherpassage for vaporized refrigerant leading from the opposite end portionof said chamber to that into which the vaporized refrigerant enters,where-by a slight pressure in said tank may sufiice to circulate coldgasthrough and out of the chamber said chamber being of larger volumethan said tank below the liquid level, whereby an article may be removedfrom said chamber into said tank for immersion while a second articlemay be retained in said chamber with the first but not removed with saidfirst article.

10. A cold treatment apparatus comprising, in combination, a tank for avaporizable liquid refrigerant, a cooling chamber, a partition in saidtank open adjacent the bottom of the tank and dividing the portion ofthe tank above the normal liquid level into separate gas spaces, aclosure for each gas space, a closure for the chamber, a passage fromeach gas space in the tank into an end portion of the chamber, and avent passage from the end portion of the chamber opposite that intowhich vaporized refrigerant is supplied.

11. A cold treating apparatus comprising, in combination, two separatevertical chambers arranged adjacent to but outside of one another andeach having an opening at its top end through which articles may beinserted into and removed from said chambers, one of said chambersconstituting a precooling chamber and the other chamber constituting atank for holding vaporizable refrigerant into which articles are adaptedto be transferred after they have been precooled in said precoolingchamber; a conduit for conducting vaporized refrigerant from an upperpor tion of said tank into a lower portion of said precooling chamber;and means for closing and uncovering the opening at the top end Of eachof said chambers.

12. A cold treating apparatus comprising, in combination, two separateVertical chambers arranged adjacent to but outside of one another andeach having a closed bottom but having an opening at its top end throughwhich articles may be inserted into and removed from said chambers, oneof said chambers constituting a, precooling chamber and the otherchamber constituting a tank for holding vaporizable liquid refrigerantinto which articles are adapted to be transferred and immersed forfurther cooling after they have been precooled in said precoolingchamber; a conduit leading from the space above the liquid refrigerantlevel in said tank into the lower part of said precooling chamber, toconduct vaporized refrigerant from said space into said precoolingchamber near its bottom; a vent adjacent the top end of said precoolingchamber for discharging vaporized refrigerant from said precoolingchamber; and movable closure means operable to close and to uncover theopening at the top end of each of said chambers.

13. A cold treatment apparatus comprising a tank for refrigerant, achamber adjacent to but outside of said tank, an outlet passage forvaporized refrigerant leading from an upper portion of said tank into alower portion of said chamber for discharge of such refrigerant into alower portion of said chamber, and an outlet passage for saidrefrigerant leading from an upper portion of said chamber into theatmosphere, said outlet passage from said tank extending downward for asubstantial distance within said chamber.

14. A cold treatment apparatus comprising a tank for refrigerant, achamber adjacent said tank, an outlet passage for vaporized refrigerantleading from an upper portion of said tank into a lower portion of saidchamber for discharge of such refrigerant into a lower portion of saidchamber, an outlet passage for said refrigerant leading from an upperportion of said chamber into the atmosphere, a pivotal closure for eachof the tank and chamber, at least said tank closure being located abovethe tank and provided with a stop to prevent said closure being openedthrough more than an acute angle to insure said closure closing upon itsrelease.

ROBERT E. BLUDEAU.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 663,456 Muller Dec. 11, 19001,877,181 Killefer Sept. 13, 1932 1,978,204 Hurt Oct. 23, 1934 2,126,1977 Lewis Aug. 9, 1938 2,197,365 Kjerrman Apr. 16, 1940 2,447,249 HillAug. 17, 1948 2,487,821 McCandless et al. Nov. 15, 1949

